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Get Fisher Information From a Design Plan

Source: R/f_design_futility_bounds.R
getFisherInformation.Rd

Calculates the Fisher information at the first planned analysis stage for a design plan for means, rates, or survival endpoints.

Usage

getFisherInformation(designPlan)

Arguments

designPlan

A trial design plan object as returned by functions such as getSampleSizeMeans(), getPowerMeans(), getSampleSizeRates(), getPowerRates(), getSampleSizeSurvival(), or getPowerSurvival().

Value

A numeric value or numeric vector containing the first-stage Fisher information. A vector is returned if the design plan contains several planning alternatives or sample size values. NA_real_ is returned if the endpoint type is not supported by this helper.

Details

The returned information is the information used at the first stage of the design plan. For group sequential designs, information at later stages can be obtained by multiplying this value by the ratio of the corresponding information rate to the first information rate.

For means, the information is based on the planned sample size, standard deviations, allocation ratio, and, if applicable, the mean-ratio null value. For rates, it is based on the planned sample size and the binomial variance under the corresponding planning assumptions. For survival endpoints, it is based on the planned number of events and the allocation ratio.

See also

getFutilityBounds()

Examples

if (FALSE) { # \dontrun{
designPlan <- getSampleSizeMeans(alternative = 0.4)
getFisherInformation(designPlan)

design <- getDesignGroupSequential(kMax = 3)
designPlan <- getPowerMeans(design,
    alternative = c(0.3, 0.4), maxNumberOfSubjects = 100
)
getFisherInformation(designPlan)
} # }